In a cellular wireless telecommunications network, radio coverage is provided by areas known as cells. A base station is located in each cell to provide the radio coverage area or cell. Traditional base stations provide coverage in relatively large geographical areas and these are often referred to as macro cells. It is possible to provide smaller sized cells, often within a macro cell. Such smaller sized cells are sometimes referred to as micro cells, pico cells or femto cells. Such small cells are typically established by providing a small cell base station that provides radio coverage having a relatively limited range, typically within the radio coverage area of a macro cell. The transmission power of the small cell base station is relatively low and, hence, each small cell provides a smaller coverage area compared to that of a macro cell and covers, for example, an office or a home. A group of such small cell base stations may together provide a wireless small cell network.
Such small cells have generally been provided where the communication coverage provided by the macro cell is poor, or where a user wishes to use an alternative communications link provided locally by the small cell base station, to communicate with the core network. Such a situation might arise where, for example, a user has a pre-existing communications link and the user wishes to utilise that link in preference to that provided by the macro cell network provider to communicate with the core network. However, increasingly, small cells are being deployed in areas of high traffic demand (often referred to as hot spots), where that demand risks overloading the macro cell. Users can then be handed over to the small cell in order to reduce the traffic load on the macro cell.
Although providing such small cells can provide many advantages, unexpected consequences can also occur.
Accordingly, it is desired to provide an improved technique for controlling the interaction between user equipment and base stations.